1. Field of the Invention
This invention relates to a food package in which food resting on a grease-absorbing pad can be cooked directly in the package by microwave energy. More particularly, the invention concerns an improvement in such a package wherein the grease-absorbing pad is a composite nonwoven fabric comprising a porous spunbonded polyester outer fabric attached to a needle-punched nonwoven polyester staple-fiber web.
2. Description of the Prior Art
Packages are known for use in microwave cooking of foods that generate large amounts of liquid grease, fat and oil. In such packages, the food usually rests on a grease-absorbing pad and is sealed in a microwave-transparent film enclosure.
Larson, U.S. Pat. No. 4,865,854, and Larson et al, U.S. Pat. No. 4,873,101, disclose such food packages for microwave cooking of bacon, sausages, and other such fatty foods. The food rests on a pad of melt-blown microfibers of polypropylene, poly(4-methylpentene-1), polyethylene, polyester, or a mixtures thereof, preferably a 50/50 mixture of polypropylene and polymethylpentene. The pad has a network of compacted high-density regions and low-density pillowed regions. Grease that is liquefied and released from the food during cooking is absorbed by the pad and amounts to 4 to 12 times the weight of the pad. The food and pad are contained in a vapor-tight enclosure that is transparent to microwaves and visible light.
Monforten et al, U.S. Pat. No. 4,786,513, and Lunquist et al, U.S. Pat. No. 4,720,410, each disclose a food package for microwave cooking of stacked slices of bacon. Sheets interleaved between successive strips of bacon direct the liquid grease that forms during cooking to an absorbent blotter. The blotter consists of a perforated thermoplastic film atop a grease-absorbing layer of molded pulp, paper or the like.
Food packages intended for crisping or browning food during microwave cooking are disclosed by Fisher et al, U.S. Pat. No. 4,892,782. The packages include fibers or substrates that are coated or imbibed with susceptor materials and require the use of much higher temperatures during cooking to crisp or brown the food.
Brown, U.S. Pat. No. 4,851,273, though not concerned with food packages for microwave cooking, discloses a wide range of pads for use in absorbing residual oils and grease that may remain on fried food immediately after the food is removed from the frying oil. The pad comprises an outer oil-permeable protective layer, which preferably is a woven polypropylene fabric, and an inner layer of absorbent material, which preferably is a nonwoven, fibrous polypropylene product. Brown discloses broad ranges of materials and characteristics for the pads, but specifically exemplifies only a pad with the preferred woven polypropylene outer fabric and the preferred nonwoven polypropylene absorbent material.
Although known food packages for microwave cooking have been used with some success, further improvements are needed to enhance their utility. For example, the short, weak, polypropylene microfibers of some absorbing pads in commercial food packages for microwave cooking often stick to the surface of the food and are pulled out of the pad when the cooked food is separated from the pad. Also, temperatures during microwave cooking of meats often are high enough (&gt;150.degree. C.) to cause softening or even melting of pad fibers. Pads made of fibers of ordinary textile decitex usually require the absence of additives or finishes that are conventionally used in the manufacture of the fibers. In this regard, one may use only substances approved by the Federal Food and Drug Administration for contact with food, such as the emulsifiers and surface active agents set forth in 21 CFR Chapter 1 (4-1-88 Edition) Section 178.3400.
It is an object of this invention to provide an improved microwavable food package wherein the above-mentioned shortcomings of known packages may be eliminated or greatly reduced.